Examine source code of Minimal Darksimple

{
  "name": "Minimal Dark",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "Screenshot (4).png"
    },
    "colors": {
      "toolbar": "rgba(51, 51, 51, 1)",
      "toolbar_field": "rgba(51, 51, 51, 1)",
      "toolbar_field_text": "rgba(120, 120, 120, 1)",
      "frame": "rgba(28, 28, 28, 1)",
      "tab_background_text": "rgba(120, 120, 120, 1)",
      "bookmark_text": "rgba(120, 120, 120, 1)"
    }
  }
}